California Code, Public Utilities Code - PUC § 33013

(a) The board shall not change the purposes, the estimated cost, the boundaries of the benefit district or zones, if any, therein, or the amount of bonded debt to be incurred until after it gives notice of its intention to do so, stating each proposed change in the purpose and stating, if applicable, that the exterior boundaries proposed to be changed are set forth on a map on file with the secretary of the district. The notice shall also specify the time and place set for hearing.

(b) The notice shall be published prior to the time set for the hearing pursuant to Section 6066 of the Government Code.

(c) The notice shall also be mailed at least 30 days prior to the hearing to all owners of real property affected by the proposed change whose names and addresses appear on the last equalized assessment roll or are otherwise known to the Board of Supervisors of the County of Los Angeles or to the district.